DEAR JOAN: Last week you wrote about the dangers of giving fish to dogs, but what about cats? Is that dangerous too? Pet food companies mostly put fish in cat food.

How about kittens?

I’m also very curious why a food would be dangerous to dogs but not cats. Maybe another column with more explanation?

Tim Campf, Bay Area

DEAR TIM: Fish in large amounts also is bad for cats. The risks are primarily the same for cats as they are for dogs. Eating a relatively steady diet of fish can result in thiamine (vitamin B) deficiency.

Thiamine is essential in cats — and dogs and humans — to process carbohydrates into energy. It’s also important in the formation of nerves and for heart function.

Cat food with fish has thiamine added into the recipe, thereby greatly lowering the risk. That’s why it’s OK to feed them cat food with fish in it, but not let them have large amounts of canned tuna.

But why do we give cats fish at all? The notion that cats are natural fish-loving creatures is sort of our own invention. Today’s house cats are descended from Middle Eastern felines that were domesticated when civilization turned agrarian and cats were needed to keep mice and other critters at bay. Before that, wild cats lived more on birds, rodents and reptiles than on fish.

It’s probably OK for kittens to eat fish kitten food, but not other fish. They need proper nutrition to get started off right.

The diets for dogs and cats aren’t all that dissimilar, but they are different animals with different nutritional needs. Meat, or protein, is at the top of the food pyramid for both cats and dogs, but cats are true carnivores, requiring a diet of meat, meat products and fat, and dogs are omnivores, eating a diet of meat and vegetables to be at their most healthful.

Dickens firmly believes that the park is his personal backyard, although his meals are served in one of the town homes next to the canal. Usually, he would come home for breakfast, take a nap, have dinner around 4 p.m., then slide under the fence, cross the canal bridge to Heather Farm and get down to business.

Business meant watching softball and soccer games, attending any wedding reception, baby shower or other party in the community center. He helped the groundskeepers by catching rats and bringing moles and gophers home for me to enjoy. He particularly liked to hang out with the guys, especially teenage boys.

When he was tired, he would play lost and run up to someone, ringing the bell on his collar. That person would check his tag and call me, and I would drive over to pick him up. There were many surprised looks when I would pull up, open the passenger door, and he would saunter over and hop in the front seat for a ride home.

Many park visitors knew him and have asked after him. He is missed. He may be living rough, but would approach anyone for a handout. If you have seen a friendly, black and white cat with white mittens and boots in the Walnut Creek, Pleasant Hill or Concord area, please let me know at suet1@astound.net or 209-715-2960.

Joan, I know that you usually don’t post missing cat info, but he is very special.